GXT 2.2.5 TreeStore DragNDrop activity not reflected in TreeStore

I have a simple DragNDrop editor to modify a tree to be persisted in my db. (Using GXT 2.2.5 can't upgrade) I have a TreePanel constructed with a TreeStore. The TreePanel is both a TreePanelDragSource and TreePanelDropTarget.
The drag/drop works fine; As a test, I used the TreeStore from an existing, open Dialog window. As I drag/drop in the editor, the other window immediately shows the changes.

However, when I fetch the TreeStore to save it as a flat tree in the database, the nodes are not rearranged in the Store. How do I get the reorganized tree structure?

// After Drag and Drop activity, get the altered three thusly:
Map<ModelData, TreeModel> viewMap =
myTree.getMyView().getTreeStore().getModelMap();

The TreeModel in viewMap is actually a BaseTreeModel.
The ModelData are the objects I originally loaded into TreeStore.
I had to:
1 - Iterate over viewMap, extract the "id" for each BaseTreeModel and create a reverse map,
indexed by the "id" and containing my ModelData objects.
2 - Fetch the root BaseTreeModel node from viewMap using the root ModelData of my original tree,
3 - Walk the BaseTreeModel tree.
At each node, fetched my ModelData objects by "id" from the reverse map.

In this way I reconstructed the tree altered by Drag and Drop, which I then persisted to my DB.